In response to your doc:

[JimMerritt]

Things I love about your write-up:

Multiple cards to pull from
The three cards or one face-down stack to draw from adds a level of complexity that would increase the strategy of it all. I do agree with the issue that a card can be covered/uncovered in an infinite loop. Maybe this can be remedied through the assassins or through a Royal Family member action? Maybe an assassin can 'clear a stack' instead of an opponent's face cards?

Starting as a member of a family with an alliance
Having a standard start sequence and story would make it easier to get into games once a player is familiar with the setup, or for the first time for that matter. That also takes the guesswork out of the setup process and makes talking about the card usage/placement much easier that 'the other red suit' or 'the other black suit'.

Royal Family Abilities
Adding a turn based on the drawing a card allows for a player to use abilities based on the current setup in their castle. That's pretty awesome. If we made it so a player can use abilities based on their active family members, that could increase strategy. So each player could have a standard draw sequence, followed by an ability. Or, they could use an ability in conjunction with an attack, or prep for defense. Maybe they can use their family abilities at any point during their own turn and some abilities prep them for defense during their opponent's turn.

Jokers as assassins
I had this same thought. My only concern was if someone doesn't have jokers in their deck for whatever reason, they may miss out on a big component of the gameplay. That's what pushed me to the twos. Twos aren't really useful for attacking since they're so low, so we could repurpose them to assassin instead of a standard attack card.

Maybe jokers could be the 'wild card' and if a joker is drawn, a player can hold onto them until they decide to use them. The way I had written the twos was to take immediate action anytime they're drawn. Jokers would be a good balance to that.

Or, with the multiple cards to pull from, twos can be held for use at any time during your turn, to assassinate one member of the opposing family. Maybe jokers can wipe out the entire family? Or maybe they're saboteurs that can get rid of a fortification card?

Need at least one family member to attack
This may be tougher to get a family member in the version with three cards to pull from. I do agree with the idea that a family member to attack is needed, otherwise there's little incentive to pulling family members unless they have some crazy abilities. Without this requirement, a player may be able to just attack outright, causing every game to be a blitz for fastest damage with little strategy. That may be way off from actual gameplay but that was my concern. In the two deck split system I wrote up, pulling family members was decently simple since one of the decks was ~66% face cards. Of those, 25% chance to pull your own (50% with two castles). That's the main reason I was splitting the decks: to give incentive to pull from the face card deck to 'stockpile' your castle, or pull from the number cards to set up your attacks and defense.

Like I said, I'm loving the multiple cards in play so I'm not saying the two split deck system would be better, that's just where I was heading with that mindset.